Hydraulic system



INVENTOR Romeo /l/ BY fM-'r N0V- 10, 1942 R. M. NARDONE HYDRAULIC SYSTEM original Filed Feb. zo, 1940 Patented Nov. 10, 1942 -UNITED STATES PATEN'I ,OFFICE HYDRAULIC SYSTEM Romeo M. Nardone, Westwood, N. .1., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Original application February 20, 1940, Serial No. 319,955, now Patent No. 2,258,159, dated October 7, 1941. Divided and this application December 26, 1940, Serial No. 371,847

1 Claim.

This invention relates to hydraulic systems, and particularly to the pressure-generating unit of such systems.

An object of the invention is to provide a pressure-generating unit adapted for inter-relation with an internal combustion engine in such manner that it may convert energy received from a storage unit into mechanical effort byvwhich` serves to transmit torque from one to the other at a different multiplication ratio, depending upon the direction of torque transmission.

These and other objects of the invention will become apparent from inspection of the following specification when read with reference to the accompanying drawing wherein is illustrated the preferred embodiment of the invention. It is to be expressly understood, however, that the draw.- ing is for the purpose of illustration only, and

is not designed as a definition of the limits of the invention, reference being had to the appended claim for this purpose.

In the drawing:

Fig. 1 is a lonliitudinal sectional view of a device embodying the invention; and

Fig. 2 is a diagrammatic view of the device as applied to the hydraulic system.

' Referring to the drawing, reference characters 5 and 6 designate two parts of a sectional housing joined together by suitable fastening means 1, the outer section 6 being closed by an end-plate 8 and the inner section by an annular cup-shaped element 9, the central portion of which has oilsealing registry with the hub portion of a jawclutch member I2 adapted to drivably engage a correspondingly shaped clutch element I0, secured to or drivably connected with the crankshaft of an internal combustion engine. The flanged portion |3 of the member 9 has openings adapted to receive bolts I6 in the anged portion |1 of the housing section 5, both said anged portions |3 and I1 being adapted to register with a correspondingly positioned flange of the engine crankcase which supports the unit shown.

Within the housing section 6 are inter-meshed.

elements of the unit during normal running of the associated internal combustion engine, and also constituting a prime mover for converting the fluid energy received from the hydraulic pressure source` (|21, Fig. 2) into mechanical elort for imparting initial rotary movement to the engine crankshaft, by way of the gear train and torque limiting clutch mechanism interposed between the pump element 22 and the engineengaging clutch element I2.A

As shown, such connections include a central shaft element 3| having one end splined as indicated'at 32 for engagement with corresponding splines of the hollow hub extension 33 of the pump element 22; the opposite end of the shaft 3| being piloted in a series of bearings as indicated at 36, 31 and 38, two of which bearings rotatably support the hub portions 4| and 42 of a pair of carrier elements 43 and 44, respectively, constituting rotating supports for two corresponding series of planet elements of the planetary gear train whose high speed .end is constituted by the sun pinion 46 which, as shown, is

integral with the shaft 3| at approximately the central section thereof; the low speed end of the planetary system being shown as taking the form of a hollow cylinder of barrel 4 9, one end of which is substantially closed and constitutes a rotatable carrier for the planet pinions 5|- which constitute the third series of planet elements of the system and which, as shown, are in driving connection with a sun pinion 52 formed on the hub 4| of the planet carrier 43. vAs shown, thethree sets` of planet elements 5|, 53 and 54 have a common orbital track 53 on which are formed three identically pitched sets of gear teeth forming, in effect, three internally-toothed'annular gears 6|, 62 and 63 for meshing relationship with the planetary pinions 5|, 53 and 54, respectively, as the latter` revolve about their individual axes and rotate about a common axis which is the axis of the shaft 3|.

The driving connection between the barrel 49 in which the planetary system terminates and the engine-engaging clutch element I2, preferably includes a torque-limiting clutch assembly composed of interleaving friction discs 1| having splined engagement in alternation with the barrel 49 on the one hand, and th'e hollow shaft 12 on the other, which shaft 12 has additional splines 13 for engagementwith corresponding splines on the hub of the clutch element I2. The engaging pressure upon the friction discs 1| is due to provision of a series of coiled comspur gears 2| and 22 constituting the pumping 55 pression springs 8| with which is associated an annular externally threaded pressure applying plate 82 adapted to be locked in the adJusted poi sition with respect to the internally threaded a slot in the member 83 and thus lock the assemu bly together.

The means whereby the torque multiplication ratio is maintained at a relatively high value during the engine starting operation and thereafter reduced (to prevent excessively high Ispeed of the pumping elements 2| and 22 with respect to the engine crankshaft speed during normal running of the engine) includes a pair of one- Way driving connections one of which takes the form of ratchet elements 9| and 92 and the other of which is contsituted by similar ratchet elements 93 and 94, the former set being constantly urged into inter-engagement by coiled compression spring 96, which spring also acts through interposed centrifugal weight elements 98 to yieldably holdratchet elements 93 and 94 in engagement until such time as the speed of rotation of the entiregear train (and hence weight carrier |8I) becomes sufficient not only to throw the weights 98 about their respective pivots 99, but also to throw the ratchetielement 94 away from engagement with its associated element 93. As shown, ratchet element 93 is integral with orbit gear 58, while ratchet element 94 is splined to stationary member 95, hence held against rotation at all times, although slidable axially in the manner just described. Pins 99 are journaled in bearings |88 extending from a cup-shaped weight-carrier |8| keyed to shaft 3|, to rotate therewith.

vTo begin the cycle of operation, valve |22 (see Fig. 2) is opened and selector valves |23 and |3| are thrown (by the common control handle |43) to positions in which conduits |25 and |25, also conduits |44 and |45, intercommunicate. `Liquid under pressure then passes from accumulator |21 to the starter by way of conduits |28, |25, |29, |28 and |2|, the latter terminating in the pump housing. Rotation is thus imparted to the gears 2| and 22, and thence to the engine crankshaft by way of intervening elements 3|, 46, 54, 42, 53, 4|, 5|, 49, 1|, 12, 'I3 and |2, heretofore indicated; the orbital gear 58 being held stationary by the ratchet teeth of ilxed element 94.`

The liquid is discharged on the opposite side of gears 2| and 22, to conduit |29, and'from there to the reservoir |38, the return path including conduit |44, return iiow selector valveA |3I, conduit |45. the shut-ot valve |32, and the conduit |33.

As soon as the engine starts, the operator closesv communication between conduits |25 and |28 (by appropriate shifting of `valve` handle |43) and the gears 2| and 22 now pump liquid from reservoir |38, by way of conduit |4|, non-return valve |42 and conduits |28 and |2|, and deliver the pumped liquid to the accumulator |21, by way of conduit |29, conduit |52, non-return valve |53, and conduit |54. 'I'his delivery replenishes the supply of liquid under pressure in accumulator |21, so that the latter may continue to serve the needs of the entire hydraulic system, not only during continued operation of the engine, but also during subsequent starting thereof. During this pumping phase of operation the drive from engine member i2 to the pump gear 22 is at a one-to-one ratio, for all planet elements now rotate as a unit due to the locking of ratchet teeth 9|, 92 and the separation of ratchet teeth 93, 94, wherefore orbital gear 58 is freed to rotate; and the speed of rotation being the same as that of engine member i2, it follows that there will be suillcient centrifugal force to hold the weights 98 in the swung-out position, thereby preventing anypossibie return of ratchet element` 94 to the gear-engaging position shown in Fig. l, until such time as the engine stops, whereupon the decelerating weights 98 will be swung back (by spring 96) to the position shown in Fig. l, thus carrying the ratchet element 94 back into engagement with teeth' 93.

This is a division of my application Serial No. 319,955, led February 20, 1940, now matured as Patent No. 2,258,159.

What I claim is:

In combination, a liquid reservoir, and an accumulator of liquid under pressure, a pump in circuit with said reservoir and accumulator, said circuit including a pair of valves and a single means for simultaneously opening or simultaneously closing both said valves, means operative only when both said valves are open, to cause flow of liquid through said pump to operate the latter as an engine starting motor, and means operative only when both said valves are closed, to deliver liquid to said accumulator by a path which leads from said reservoir and includes said pump.

ROMEO M. NARDONE. 

